Optimum Surface Texture Geometry

Abstract

A surface geometry for an implantable medical electrode that optimizes the electrical characteristics of the electrode and enables an efficient transfer of signals from the electrode to surrounding bodily tissue. The coating is optimized to increase the double layer capacitance and to lower the after-potential polarization for signals having a pulse width in a pre-determined range by keeping the amplitude of the surface geometry with a desired range.

1 . A coating for an implantable medical electrode comprising a zone 2 microstructure composed of a primary metallic component and a secondary reactive component, said surface having crystals with a [1, 1, 1] structure defined thereon, said crystals having an average amplitude in a desired range. 
     
     
         2 . The coating of  claim 1  wherein said desired range is approximately 250-400 nanometers. 
     
     
         3 . The coating of  claim 1  wherein said crystals are pyramidal in shape. 
     
     
         4 . The coating of  claim 3  wherein said pyramids are three- or four-sided structures. 
     
     
         5 . The coating of  claim 1  wherein said coating is a nitride of an element selected from the group consisting of Ti, Ta, Nb, Hf, Zr, Au, Pt, Pd and W.